[PATCH 2/3] KVM: nVMX: allow setting the VMFUNC controls MSR

[Paolo Bonzini]

Allow userspace to set a custom value for the VMFUNC controls MSR, as long
as the capabilities it advertises do not exceed those of the host.

Fixes: 27c42a1bb ("KVM: nVMX: Enable VMFUNC for the L1 hypervisor", 2017-08-03)
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
---
 arch/x86/kvm/vmx/nested.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index c4e29ef0b21e..163d226efa96 100644
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -1234,6 +1234,11 @@ int vmx_set_vmx_msr(struct kvm_vcpu *vcpu, u32 msr_index, u64 data)
 	case MSR_IA32_VMX_VMCS_ENUM:
 		vmx->nested.msrs.vmcs_enum = data;
 		return 0;
+	case MSR_IA32_VMX_VMFUNC:
+		if (data & ~vmx->nested.msrs.vmfunc_controls)
+			return -EINVAL;
+		vmx->nested.msrs.vmfunc_controls = data;
+		return 0;
 	default:
 		/*
 		 * The rest of the VMX capability MSRs do not support restore.
-- 
1.8.3.1